The invention concerns a sensor for obtaining information about the state of an organism for a medical therapy apparatus, preferably for a therapy apparatus for the electrostimulation or other treatment of the heart.
Sensors of that kind are known from the state of the art. The items of information which are detected thereby are required by the medical therapy apparatuses in order to be able to operate in the optimum fashion. Thus for example sensors for therapy apparatuses for electrostimulation of the heart, in particular sensors for cardiac pacemakers or for defibrillators, detect cardiac disrhythmias, but sensors of electromedical apparatuses can also measure muscle activity, lung function parameters, oxygen saturation, blood pressure, hormone level or other physiological parameters. All those parameters can be used for controlling the pacemaker or the defibrillator.
In that respect, particularly in the case of cardiac pacemakers, it is important for the stimulation pulse produced by the pacemaker to be matched in terms of its stimulation amplitude to the stimulation threshold. The stimulation threshold characterises that stimulation amplitude of the pacemaker, which is required in order to trigger a stimulation outcome, that is to say a stimulated systole. As the stimulation threshold can vary as a consequence of hormone level, time of day, physical activity and so forth, it is advantageous if the stimulation amplitude can be adapted to that variation in the stimulation threshold. In that respect, the stimulation outcome itself can also be used for controlling the pacemaker. For, if for example the absence of a stimulation outcome after the delivery of a stimulation pulse (as a result of the absence of a rise in impedance in the impedance pattern after delivery of the stimulation pulse) means that a sub-threshold stimulation situation is detected by a suitable sensor, then the stimulation amplitude is to be increased in order to further ensure reliable functioning of the pacemaker. To sum up it can be noted that, in the case of electromedical therapy apparatuses, particularly in the case of cardiac pacemakers and defibrillators, optimisation of the function of the apparatus is all the more possible, the greater the number of parameters involved in control or regulation of the apparatus.
Therefore the object of the present invention is to so develop a sensor of the kind set forth in the opening part of this specification, that additional parameters which were hitherto not detected in the state of the art can be detected.
In a sensor of the kind set forth in the opening part of this specification, that object is attained in that there is provided at least one sensor element for detecting molecular-genetic information.
In addition the invention provides a medical therapy apparatus, in particular a cardiac pacemaker or a defibrillator, which has a sensor of that kind.
The advantages of the invention are in particular that detection of molecular-genetic information means that a further parameter is available, for controlling a medical therapy apparatus. A sensor of that kind, which like the therapy apparatus itself can be disposed inside or outside the body, can thus advantageously detect for example genetic defects which result in a change in the stimulation threshold in the case of pacemakers. In that way a medical therapy apparatus which is so equipped can also adapt the stimulation threshold to particularities of that kind which permanently prevail in the respective organism. The sensors according to the invention can be part of a therapy apparatus, in module-like fashion, so that they can be interchanged at any time or can also be subsequently added. The sensors according to the invention can however also be a fixed integral component part of a medical therapy apparatus.
Furthermore, by virtue of the invention, it is advantageously possible also to determine genetic or biological indicators, besides clinical indicators for cardiac disrhythmia phenomena or other malfunctions of the organism. In that way, by virtue of the invention, for example particular susceptibility on the part of the organism to cardiac disrhythmias or also for given kinds of cardiac disrhythmias can be determined or detected at an early stage. If such a sensor according to the invention is then part of a medical therapy apparatus, then having regard to such a genetic parameter it is possible to determine an indicator signal as a measurement in respect of an imminent event which is in need of therapy. Certain physiological states of the organism, which require treatment, can thus already be detected at the outset and thus the use of suitable therapy measures on the part of the therapy apparatus can be initiated or prepared.
In an advantageous embodiment of the invention the sensor element has at least one docking element, to which docking element molecules of the organism can be docked, wherein the docking specificity of the docking element is known. It is thus possible by means of such a docking element to ascertain whether given molecules are present in the organism. If in that respect the docking specificity of the docking element is for example so set that certain genetic defects which manifest themselves in certain molecules, of a specific configuration, in the organism, can be detected in that manner, then the sensor can detect that genetic effect and possibly signal same to a therapy apparatus. The therapy apparatus can then in turnxe2x80x94possibly after setting or enablement by the doctorxe2x80x94again initiate a suitable therapy measure or adapt the strength of the therapy measure to the detected genetic defect. In the case of cardiac pacemakers, in this connection the stimulation threshold can be raised or lowered according to the known effects of the detected genetic defect.
In order to detect the above-mentioned known molecules, the docking element itself can include a known molecule. Those known molecules are preferably synthetic oligonucleotides or PCR-generated cDNA fragments. By means of such oligonucleotides or cDNA it is possible to bind complementary DNA pieces of the organism to be investigated. As the oligonucleotides or cDNA fragments serving as docking elements are known, that means that the bound DNA piece is also known. The presence of a given DNA piece then makes it possible to infer back to a given state of the organism or a morbid change in the organism. In that way for example it is also possible to ascertain the presence or the amount of given enzymes in the organism. That can be helpful in terms of early detection of a cardiac infarct.
In a further preferred embodiment the sensor elements are preferably provided at least twice on the sensor. In that way random bindings of molecules to the docking elements can be recognised as being random and excluded in regard to evaluation of the measurement result.
In a particularly preferred feature the sensor according to the invention includes measuring elements which are preferably connected to each sensor element, which measuring elements detect hybridisation of a complementary molecule of the organism to the known molecule serving as the docking element. The measuring elements in that respect may be a current measuring element for measuring an electrical current produced by the hybridisation procedure, a fluorescence measuring element for detecting a fluorescence which is present due to hybridisation, a charge measuring element for detecting an electrical charge distribution altered by hybridisation, or a radiation measuring element for detecting radioactive radiation present due to hybridisation. If for example the arrangement involves a measuring element for detecting fluorescence, the DNA or RNA to be investigated in the organism is suitably provided with fluorescence markings. If a DNA or RNA marked in that way is hybridised with the complementary sequences on the sensor, that fluorescence and thus the hybridisation can be detected with the fluorescence measuring element.
In a particularly preferred embodiment of the present invention the known molecules serving as docking elements are arranged in a plurality of rows in mutually juxtaposed relationship in a chessboard-like configuration. Then, oligonucleotides or cDNA fragments which are characteristic of a given genetic defect or a given molecular-genetic state are arranged on that sensor which is provided with the sensor elements in a chessboard-like configuration, in a given sequence or a given pattern. In regard to that pattern, it is in turn known in what fashion, with a known genetic defect, the DNA or RNA of the organism which has that genetic defect binds to the molecules arranged in the chessboard-like configuration. Thus, a given binding or hybridisation pattern is known for a given gene or a given genetic defect. That hybridisation pattern can be stored for example in a storage means or memory of the sensor. If the sensor is then used to investigate an organism, the pattern which is then actually present can be detected by means of the measuring element and compared by means of a comparison device to the stored hybridisation patterns. If then the comparison device establishes identity of the current hybridisation pattern with a stored hybridisation pattern, the sensor is thus capable of ascertaining the presence of a given genetic defect or also a given molecular-genetic state of the organism being investigated. In that respect, it is also possible to ascertain the variation in respect of time of the hybridisation pattern. In that way it is possible for example to understand the expression of given genes. Such a measured expression of given genes in turn makes it possible to draw conclusions about a given state of the organism. If for example it is ascertained by means of the sensor according to the invention that given genes are expressed in the organism, which are expressed only in a given morbidly changed state of the organism, the sensor can then produce a corresponding signal which signals for example to a medical therapy apparatus the genetic defect of the organism or the morbidly changed expression of given genes. The morbidly increased production of given enzymes can also be ascertained in that way.
The above-mentioned known molecules are preferably arranged on a support substrate of glass, gel-coated glass, nylon, silicate, silicon or gallium arsenide. Suitable measuring elements are then preferably connected to the support substrate. In that respect, it is particularly preferred in accordance with the invention if the measuring elements are measuring elements for measuring an electrical current. In that way, the idea of the invention can be implemented in a particularly simple fashion insofar as an electrical current or a change in the electrical current when hybridisation has occurred with a molecule is measured at each sensor element.
In a further preferred embodiment, arranged on the chessboard-like sensor are cDNA fragments which are characteristic in respect of the expression of genes for given hormones. In that way, by means of the sensor according to the invention, it is also possible to record the hormone balance of the organism being monitored, in particular the presence or excess of a given hormone. Particularly if the medical therapy apparatuses of the invention involve cardiac pacemakers or defibrillators, it is of great importance to be able to detect given hormones in the body at an early stage. For, in particular the stimulation threshold for a cardiac pacemaker is inter alia dependent on a given hormone level in the organism. Then, in the case of such a cardiac pacemaker which is equipped with a sensor according to the invention, the pacemaker can be used in optimised fashion in terms of its function, by virtue of molecular-genetic detection of the hormone level by means of the sensor according to the invention.
It is also advantageous if the sensor element according to the invention or the medical therapy apparatus, in particular a medical therapy apparatus for the electrostimulation or other treatment of the heart, is provided with a sensor means at the input side, for producing at least one input signal which as an indicator signal forms a measurement in respect of a therapy threshold or a necessary level of therapy intensity. In that way the therapy threshold or intensity can be automatically set to the genetic predisposition of the patient.
It is particularly advantageous if, in the case of an electromedical apparatus which is adapted to be implantable, the indicator signal at least indirectly forms an input signal for a programming device which serves at least indirectly for setting at least one therapy or operating state parameter of the therapy apparatus. In that way the therapy apparatus can already be individually (pre-)set for a given patient upon manufacture or immediately after implantation. In this respect a corresponding production process for a medical therapy apparatus is also subject-matter of the invention.
In a preferred embodiment of a medical therapy apparatus of that kind, an addressing signal can be produced for a storage means or memory by means of the at least one indicator signal, which addressing signal in the manner of an addressable table (look-up table) contains in respective various storage regions which can be selected by the addressing signal in dependence on the indicator signal items of therapy information which can be read out as output signals and which are associated with the respective indicator signal.
Further preferred embodiments of the invention are set forth in the appendant claims.